(1) Field of Invention
The present invention relates to three-dimensional imaging and, more particularly, to a method and system for fast three-dimensional imaging using defocusing and feature recognition.
(2) Description of Related Art
The present invention relates to three-dimensional imaging. The various methods for imaging objects in three-dimensions can be divided into scanning methods and instantaneous methods. Scanning systems are generally suitable for imaging immobile objects. Scanning methods include laser scanning, ultrasound (tomography), magnetic resonance imaging (tomography), and confocal scanning microscopy. Instantaneous systems can be used to capture moving objects and thus analyze motion, such as in defocusing DPIV (Digital Particle Imaging Velocimetry). Other instantaneous methods include ultrasound, three-dimensional photogrammetry, correlation surface mapping, and time-of-flight systems.
Currently existing instantaneous imaging methods using defocusing involve imaging an object with markers applied to or projected onto the surface of an object, or using natural features or texture in the object to analyze its shape and location in space. These methods are “dumb” in that they are generalized (i.e., they do not inherently understand the object being imaged). This generalization leads to a system whose resolution is dependent on the number of points analyzed. As such, the processing time increases.
Thus, a continuing need exists for a method for fast three-dimensional imaging using defocusing which reduces processing time by incorporating a priori knowledge of the object being imaged.